Question: Simplify the following expression: $p = \dfrac{k}{4} - \dfrac{4k}{3}$
Solution: In order to subtract expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $4$ and $3$ $\lcm(4, 3) = 12$ $ p = \dfrac{3}{3} \cdot \dfrac{k}{4} - \dfrac{4}{4} \cdot \dfrac{4k}{3} $ $p = \dfrac{3k}{12} - \dfrac{16k}{12}$ $p = \dfrac{3k -16k}{12}$ $p = \dfrac{-13k}{12}$